$OpenBSD: patch-viz_c,v 1.3 2013/11/16 01:45:38 naddy Exp $
--- viz.c.orig	Fri Apr 14 15:30:56 1995
+++ viz.c	Sat Nov 16 02:40:57 2013
@@ -51,18 +51,23 @@
 #include "string.h"
 #include "memory.h"
 #include <errno.h>
+#include <stdlib.h>
+#include <unistd.h>
 
 #define VIZ_MAIN
 #include "viz.h"
 
+#ifndef _SYS_ERRNO_H_
 extern errno;
 extern int sys_nerr;
 extern char *sys_errlist[];
+#endif
 
-
+#ifndef _STDLIB_H_
 extern char *malloc();
 extern optind, opterr;
 extern char *optarg;
+#endif
 
 char *prog;
 struct Format Fmt = {
